A wide variety of sanitary articles are known in the art for taking up menstrual fluid, e.g. sanitary towels (pads) and tampons. Sanitary towels have the drawback of being visible, since they are carried outside the body and also change position with body movements. Further, they may entail transfer of intestinal bacteria to the vagina. Many women therefore prefer tampons as protection against menstrual fluid, especially women who lead an active life.
During low production of menstrual fluid, the conventional tampon provides great friction which results in uneasiness to insert and withdraw as well as dryness of the vaginal mucosa. Women would prefer to use tampons exclusively if there are no side effects e.g. leakage, discomfort with insertion and withdrawal and no medical risks.
During the menstrual period women bleed on average 40 ml (1600 drops/5 days), and eighty percent of the total bleeding occurs during the first two days (106 drops/4 hours); thus during the three remaining days, women only bleed 8 ml (16 drops/4 hours). (Hallberg L, et al: Menstrual blood loss—A population study. Acta Obstet Gynecol Scand 45:320, 1966; Hallberg L, Nilsson L: Determination of menstrual blood loss volume. Scand J Clin Lab Invest 16:244, 1964; and Rybo, G, 1966, Menstrual blood loss in relation to parity and menstrual pattern, Acta Obstet Gynecol Scand 45 (Suppl7), 25-45).
Conventional tampons have an approximate maximal absorption capacity of 320 drops during the first second.
Hence, in view of the amount of menstrual fluid produced, conventional tampons have a significant overcapacity. The moisture balance in the vagina also supplies a moistured film to the vaginal mucosa. This moistured film is disturbed by use of a conventional tampon.
Moreover, the use of certain contraceptive agents, such as contraceptive pills, further reduces the amount of menstrual fluid during the menstrual period.
As a result of this major overcapacity, there is a great risk that the vaginal tissue will be dried out by the use of a tampon, especially during the later stage of the menstruation period. As a consequence, the risk for disturbances of the vaginal microbiota and the risk for infections is significantly increased.
A severe disease, which has appeared among tampon users, is called the toxic shock syndrome (TSS). TSS is caused by the uptake of bacterial toxins in the vaginal tissue. The risk for contracting TSS increases when the vaginal tissue is dried out, since then micro-wounds will easily result, which cause invasion of bacteria.
Accordingly, the overcapacity of conventional tampons is a great disadvantage which could impose severe medical risks to the users. Additionally, many women experience the friction of the tampon against the vaginal tissue as very discomforting, especially during insertion, withdrawal and use of the tampon.
In order to better adapt the absorption capacity of tampons to the actual need, tampons of different sizes have been produced, which shall be used during different stages of the menstrual period. However, the absorption capacity, even of the smallest available tampons, still widely exceeds what is required.
One example of a prior art tampon is disclosed in WO 03/043557, which describes a catamenial tampon comprising a generally absorbent member and a fluid wicking overwrap covering the absorbent member, said overwrap having an agar shear force of less than 90 grams. Since the agar shear force is less than 90 grams, this overwrap causes less discomfort for women by insertion, withdrawal and use of the tampon.
Until now, the problem with the overcapacity absorption of tampons has not been solved. There is therefore a great need for an improved tampon which does not adhere to the vaginal tissue or dry out the vagina, while leakage at the same time is avoided.